Chair base and seat post adjustment



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June 7, 1960 Filed Aug. 6, 1956 R. J. BUETTNER ETAL 2,939,514

CHAIR BASE AND SEAT POST ADJUSTMENT 3 Sheets-Sheet l F4 vmam: J. aaernvsn W01. r52 1?. Sig-veer Jay/v F. $7050 an M16- ron/ J. Poem/Jul 6v Av-M,LM1 AM A T70R08 Y! June 7, 1960 R. J. BUETTNER ETAL 2,

CHAIR BASE AND SEAT POST ADJUSTMENT 3 Sheets-Sheet 2 Filed Aug. 6, 1956 Mayra/es PH vMa/va J. Euzrrwm? NR4 rER P. 5/51/1991- JOHN F. 5/0 600R M. ra/v J- Eaawsaw 8/ MY M11 4 ATTOtIV'YJ WMWMWNMMWMN June 7, 1960 J BUETTNER ET AL 2,939,514

CHAIR BASE AND SEAT POST ADJUSTMENT Filed Aug. 6, 1956 3 Sheets-Sheet 3 INVENTdR$ Rn YMa/vo J. aae'r wse W94. r52 2 slave-2r JOHN F. svaaaan MIA-70M J. fiaamsw/ AM, MZHM 2,939,514 A CHAIR BASE AND SEAT POST ADJUSTMENT RaymondJ. Buettner, West Allis, Walter R. Sievert, Wauwatosa, and John F. Svoboda, Milwaukee, Wis, and Milton J. RobinsomLake Forest, Ill., assignors, by mesne assignments, to Precision Metal Workers, Chicago, 111., a partnership of Illinois Filed Aug. '6, 1956, Ser. No. 602,173 11 Claims. c1.- 155- 94 This invention relates to a chair base and seat post adjustment.

The base portion of the chair desirably comprises a plurality of legs formed in a one-piece stamping. The individual legs comprise downwardly opening channels which are marginally flanged and connected with a central spider. There are special caster mounting brackets at .the ends of the legs and trim attached to the legs is interlocked with the caster brackets to complete the base assembly. ,v

Within the base a sleeve connects the spider with the top of the stamping which provides the legs. This sleeve serves as a guide for the vertically'adjustable seat post. For purposes of adjustment, the seat post'is provided with annular teeth which present relatively sharp shoulders downwardly and are beveled on their upward surfaces for coaction with an escapement latch mounted on the base. This latch comprises a plate desirably apertured to receive the seat post and pivoted or otherwise mounted for movement with respect thereto. The two sides of this latch plate are offset approximately the distance of one tooth of the seat post so that as one side of the plate clears a tooth supportedthereby, the other side of the plate passes beneath the next tooth of the seat post to provide continued support for the post. When the plate is oscillated back to. its initial position respecting the post, the post will descend one tooth to a new position of support on the side support. 'i.

The plate is provided with'a handle for'its manipulation and with a spring biasing it toward the normal support position. Hence the plate always returns to normal support position after being manually oscillated away from that position tolower the post one tooth as a result of the described escapement operation.

The spring desirably holds the plate in its normal position with suflicient bias so that the chair can be lifted by means of its seat or 'its back without going out of adjustment. However; because of the beveled upper surfaces of the several teeth, it is readily possible to exert suflici ent tension to draw the post up through the escapement mechanism, the plateratcheting back and forth to accommodate this movement. be held to the floor by means of the operators foot during this raising operation.

A feature of the chair base is the provision of a simple inexpensive but effective sound deadening organization.

"In the drawings:

Fig. 1 is aview int-perspective of a chair base embodying the invention, the seat post being broken away.

Fig. 2 is an inverted plan view of the base shown in Fig. l with the caster mounting brackets omitted.

Fig. 3 is aview in perspective of the inseit spider used in the base.

. Fig. 4 is a fragmentary view. in vertical section in a front to rear plane through the base.

The base will ordinarily *atent O of the plate which normally provides 7 21 514 l atented June '7, 19 60 Fig. 5 is a view in perspective of a sound deadening insert used in each leg of the base.

Fig. 6 is a view in perspective of the caster mounting bracket.

Fig. 7 is a view taken in section on the line 7-7 of Fig. 4. 7 7 a Fig. 8 is a view taken in section on line 8-8 of Fig. 4.

Fig. 9 is a view taken in section on line 99 of Fig. 4. Fig. 10 is a view taken in horizontal section on line 10-10 of Fig. 4. Fig. 11 is a. detail view in perspective of the escapement plate.

Fig. 12 is a fragmentary detail view taken in vertical section at right angles to the plane of Fig.4 showing the escapement plate in its normal support position.

Fig. 13 is a view similar to Fig. 12 showing the escapement plate oscillated to lower the seat post a distance of one tooth. r

The stamping 15 provides in one piece a central hub 16 and any desired number-of legs 17, for being illustrated. The legs have the form of inverted channels. Marginal flanges 18 are continuous about the lower margins of the legsexcept adjacent the closed end portions 19 thereof. Supported on the flanges 18 and filling the center of the stamping is a spider 20 which is shown in detail in Fig 3 and is generally cruciform, extending into the several legs for'a short distance and having marginal flanges at 21 resting on the flanges 18 of the legs. The spider 20 and the stamping 15 have aligned apertures bordered by marginal annular flanges 23 and 24 to which the seat post guide tube 25 is welded or otherwise secured. The spider is also desirably welded to the stamping 15.

a At the end of each leg there is provided a caster bracket 26 separately illustrated in Fig. 6. It comprises depending wings 27 resting on leg flanges 18 betweenthe sides 'of the leg (Fig. 7). There is a central opening bordered by a marginal flange 28 to brace the socket tube 29 which receives and supports the stem of a conventional caster 30. Atthe end of the caster bracket is.adependingann at $1 with which there is engaged the hooked end" 33 of a strip of trim at 34.. This trim is 'hookedinto .po sition about "the end of-the leg, folded onto the top of theleg and secured by any appropriate meanssuch as the rivet 35 (Fig. 4).

'To damp vibrations of the sheet metal sides of the leg, I introduce inserts 37, one of which is shown in detail [in Fig. 5. .Each of these inserts'comprises a channel'with upwardlyffolded sides desirably, though not necessarily, downwardly beveled along'their top margins so that the sides are non-rectangular. The insert may be made of any suitable material, -the materials being somewhat elastic so that the insert, when positioned on the inturned flanges 18,- will retain its position due to the expansion of its side flanges outwardly against the sides of the leg. The material used desirably has little or no capacity for vibration on its own account or has such low periodicity that it can damp vibration of the sheet metal forming the leg. Moreover, the fact that it is not secured to the sides of the leg other than by frictional engagement therewithin consequence of its own tendency to expand, permits friction between the insert and the leg to assist in the desired damping of vibration occurring in the sheet metal. I have found ordinary corrugated board to serve all purposes.

Since it is entirely immaterial to the present invention how the seat 38 is constructed or what kind of a support 39 mounts it at the upper end of seat post 40, these parts have been only fragmentan'ly illustrated. The seat post 40 may comprise a bar telescopically reciprocable within the, guide tube 25. It also passes through, and is steadied by, an annular flange 41 in the escapement housing 42 which is welded or riveted or otherwise fastened on the base'15.

Throughout a considerable part of its length, the seat post is provided with annular teeth 43, the under surfaces of which are desirably abruptly shouldered at 4 while the upper surfaces of the respective teeth are beveled as shown at 45. These teeth may be. uniformly spaced to permit uniform incrementsof height adjustment of the seat post.

The seat post is adjustably supported by means of an escapement plate 50 which is movable respecting the post. In the desired arrangement illustrated, the plate ispivoted to the base at 51 and has an aperture at 52 through which the post extends. The over-all width of this aperture is less than the over-all width .of the post by an amount which is equal to the radial thickness of a tooth at one side of the post only; The sideof the plate at 53, at one side of the aperture, normaly rests beneath one tooth to provide support for the post. The margin 54 of the plate at the other side of the aperture is offset upwardly from the plane of the plate bya distance approximately equal to the vertical thickness of'a single tooth. The offset is clearly shown in Figs. 11 to 13 inelusive.

A tension spring 55 having a fixed anchorage at 56 on the base is connected to an upstanding lug 57 on the escapement plate 50 to hold the plateunder considerable bias in the normal position illustrated in Figs. .10 and 12. The plate can be oscillated from this position by manipulation of a handle 58 which projects forwardly through a slot 59 in the front of the escapement housing 52. An upstanding car 60 on the forward end of the escapement plate 50 is threaded to provide a convenient means for connecting handle 58 with the plate.

Since the clearance between the margins of the escapement plate is less than the over-all diameter of the post, we have provided at 62 a flat face on the side of the untoothed lower end of the seat post. When this flat face registers with one of the margins of the escapement plate 50, it permits the post to pass through the plate. The flattened surface 62 is preferably offset 90 from the position normally occupied by the post in use. Accordingly, after the post has been manipulated through the escapement plate to a level such'that the lowest tooth space registers with the plate, the post is rotated 90 and a pin 63 is passed through it, the ends-of the pin remain in the slots 64 of the guide tubeZS to maintain thepost against rotation from the positionin which it is shown in Fig. 4. i

As will clearly appear from a comparison of Figs. '12 and 13, the oscillation of the plate from the normal position of Fig. 12 against the bias of spring 55 to the posi- I tion illustrated in'Fig. 13 will result in withdrawingthe supporting margin 53 of the plate 50 from beneath one of the teeth 43 of the seat post 40. However, before the plate margin 53 is completely withdrawn from beneath the tooth, the elevated plate margin 54 will pass above that tooth into a position in which it will underlie the'next higher tooth of the seat post. Thus, when the seat post is released from the normal supporting margin 53, it will descend only for a distance less than the spacing between two consecutive teeth, this being the distance required to permit its next higher tooth to engage the elevated margin 54 of the escapement plate 50. w

When the operator then releases the handle 58, or permits the manually controlled spring biased return of the plate back to its normal position, the elevated margin 54 of the plate will now pass, from beneath thehigher tooth and the seat post will complete its descent for the full distance of one tooth, such higher tooth'now coming to rest on the normal supporting margin 53 of plate 50. Obviously the operation may be repeated as often as may be desired, the post being lowered one tooth in the course of each forth and back reciprocation of escapement plate 50.

When it is desired to raise the post, it is only necessary to pull upwardly on the seat. If the base is stationary, the post will ratchet readily past the escapement plate, the beveled surfaces of each successive tooth engaging the supporting margin 53 of the plate to force the plate aside and to permit the passage of that tooth. As each tooth passes, the plate will spring back to its original position and if the lifting thrust is continued, the plate will be forced aside again-by the next successively lowered tooth.

Desirably, the spring which biases the plate to its normally supporting position is made strong enough so that this upward ratcheting movement of the post will not be accommodated unless the pull on the post exceeds the weight of the base. It is frequently desirable to move a chair by lifting it by its back' or seat and under these circumstances it is not desired thatthe base ratchet downwardly to destroy the adjustment or perhaps to bring about a separation of the base from the seat post. Accordingly the spring 55 is desirably of such strength that when the seat is lifted, the base will come with' it unless the weight of the base is supplemented by some other pressure, such as can readily be exerted by the operators foot whenever it is desired to pull the seat post upwardly respecting the base.

While ordinarily a seat may be swiveled at the top of such a seat post, the annular form of the teeth with which the present seat post is provided permits the post in its entirety to. swivel with regard to the supporting margin 53 of the escapement plate by which it is supported on the base. In other words, there is no required orientation of the seat post with regard to the base and the seat post may, in fact, be rotated to any position without affecting in any manner the operation of the escapement either upwardly or downwardly. It will be understood that the embodiment illustrated is a preferred embodiment of our invention and the details thereof have many advantages. However, except as these details are included in the accompanying claims, we do not wish to be limited thereto.

We claim:

1. The combination with a chair base and a seat provided with teeth, of an escapement plate reciprocable in a generally horizontal plane on top of the base and provided with vertically offset margins alternately engageis pivoted to the base and provided with a handle for its reciprocation forth and back and is provided with means biasing it toward a position in which one of its tooth engaging margins is normally in post supporting position beneath a selected tooth.

3. The device of claim 1 in which the several teeth are annular and comprise abrupt shoulders on their lower surfaces and conically beveled upper surfaces.

4. The combination of a chair base, a seat post provided with annular teeth, an escapement plate mounted on the base and reciprocable transversely of said post and provided with a handle for its reciprocation and with tooth engaging margins laterally spaced by a distance less than the over-all diameter of the post and teeth by the radial thickness of a tooth atone side of the post, the said margins being vertically offset to receive a tooth between them, and spring means biasing said plate to engage one of its margins normally beneath a tooth in operative post supporting position, handle controlled movement of the plate from said position against the bias of said spring being adapted to release the supported tooth from'said one margin and to engage the other margin of the plate beneath a higher tooth.

5. The device of claim 4 in which the plate is pivoted to the base and provided with a hole through which the post extends and at the sides of which the vertically olfset margins of the plate are located, the base having a housing enclosing the plate and spring and provided with a slot through which the handle is exposed.

6. The device of claim 4 in which the chair base comprises a stamping from which leg portions project integrally, the said leg portions having sides constituting inverted channels and provided with inwardly turned bottom marginal flanges, the base including a guide for said post and a bottom portion to which said guide is connected and comprising a spider having legs resting on said flanges and connected with said stamping.

7. The device of claim 6 in further combination with sound damping means internally engaging side walls of the respective leg portions of said stamping.

8. The device of claim 6 in further combination with sound damping inserts of channel shaped cross section and comprising sides outwardly biased against the sides of said leg portions and frictiona-lly engaged therewith and comprising sound damping material.

9. A chair base comprising in an integral stamping a plurality of legs comprising downwardly opening channels and a central portion from which the several legs radiate, the central portion including a top wall from which the tops of the channel project, the stamping further being provided along its lower margins with inwardly turned marginal flanges which are substantially continuous to points adjacent the ends of the legs, a spider disposed beneath the top wall of the stamping and providing a bottom wall for the base, the spider extending into the leg portions of the base and being provided with marginal flanges overlying flanges of the base, caster brackets disposed between the sides of the leg portions adjacent the ends thereof and overlying the said marginal flanges of the base, and vibration damping means mounted on the flanges of the base between the spider and the caster brackets in the several legs.

10. The device of claim 9 in which each such damping means comprises an upwardly opening channel {having resiliently divergent sides frictionally engaging the sides References Cited in the file of this patent UNITED STATES PATENTS 464,319 Parsons Dec. 1, 1891 596,204 Eccleston Dec. 28, 1897 869,777 Hahne Oct. 29, 1907 2,393,242 Flogaus Jan. 22, 1946 2,490,210 Cramer et al. Dec. 6, 1949 2,514,095 Schreiber July 4, 1950 2,542,480 Cramer et al Feb. 20, 1951 2,587,886 Pencheon Mar. 4, 1952 2,740,464 Hamilton Apr. 3, 1956 2,780,277' Ries et al. Feb. 5, 1957 FOREIGN PATENTS 1,881 Great Britain Oct. 26, 1905 

